2.14 Microencapsulation
47
fabric. The microcapsules were able to withstand up to 15 laundering cycles. It was
revealed by scanning electron microscopy (SEM) that the smaller capsules survived
more effectively after laundering.
Shin et al. [242] developed a thermo-regulating textile material with microencapsulated PCM and added this to polyester knit fabrics by a pad–dry–cure process. The
microcapsules thus produced were spherical in shape with melamine-formaldehyde
shells containing eicosane. The morphology, thermal properties and laundering properties were investigated. It was found that the microcapsules were stable under stirring in hot water and an alkaline solution. The heat storage capacity of the fabric
was increased with increased concentration of the microcapsules. The heat storage
capacity of the thermo-regulating fabrics was 0.09–4.44 J/g which was retained up
to 40% even after five laundering cycles.
Hawlader et al. [250] prepared encapsulated paraffin wax by complex coacervation and spray drying methods and characterised them. The results of a differential
scanning calorimeter (DSC) showed that the microcapsules prepared by both coacervation and the spray drying method possess a thermal energy storage/release capacity
of about 145–240 J/g. Therefore, encapsulated paraffin wax is a good candidate for
solar-energy storage material. Rodrigues et al. [251] microencapsulated limonene
for textile applications by interfacial polymerisation and characterised them.
Accordis (formerly Courtaulds Fibres, in Bradford, UK) developed the technology
of in-fibre incorporation of Outlast microcapsules, loading the fibre with 5–10% of
microcapsules [155]. The process utilises late injection technology that is also used to
produce the antimicrobial fibre Amicor. In this way, the PCM is permanently locked
within the fibre, and no change is necessary in subsequent fibre processing (spinning,
knitting, dyeing, etc.). The fibre exhibits its normal properties of drape, softness and
strength.
2.14.6 Advantages and Disadvantages of Microencapsulation
Although there are many advantages in fibres and fabrics that contain microencapsulated PCM, there are a few disadvantages of the process, which are discussed
below.
2.14.6.1 Fibres
Advantages
• The PCM is permanently embedded within the fibre.
• The process parameters during spinning, knitting, dyeing, etc., are not altered for
the fibres containing the microcapsules of PCM.
• The fabrics produced from the yarn containing the microencapsulated PCM in
the fibres show the normal properties of drape, softness, comfort, etc.
47
fabric. The microcapsules were able to withstand up to 15 laundering cycles. It was
revealed by scanning electron microscopy (SEM) that the smaller capsules survived
more effectively after laundering.
Shin et al. [242] developed a thermo-regulating textile material with microencapsulated PCM and added this to polyester knit fabrics by a pad–dry–cure process. The
microcapsules thus produced were spherical in shape with melamine-formaldehyde
shells containing eicosane. The morphology, thermal properties and laundering properties were investigated. It was found that the microcapsules were stable under stirring in hot water and an alkaline solution. The heat storage capacity of the fabric
was increased with increased concentration of the microcapsules. The heat storage
capacity of the thermo-regulating fabrics was 0.09–4.44 J/g which was retained up
to 40% even after five laundering cycles.
Hawlader et al. [250] prepared encapsulated paraffin wax by complex coacervation and spray drying methods and characterised them. The results of a differential
scanning calorimeter (DSC) showed that the microcapsules prepared by both coacervation and the spray drying method possess a thermal energy storage/release capacity
of about 145–240 J/g. Therefore, encapsulated paraffin wax is a good candidate for
solar-energy storage material. Rodrigues et al. [251] microencapsulated limonene
for textile applications by interfacial polymerisation and characterised them.
Accordis (formerly Courtaulds Fibres, in Bradford, UK) developed the technology
of in-fibre incorporation of Outlast microcapsules, loading the fibre with 5–10% of
microcapsules [155]. The process utilises late injection technology that is also used to
produce the antimicrobial fibre Amicor. In this way, the PCM is permanently locked
within the fibre, and no change is necessary in subsequent fibre processing (spinning,
knitting, dyeing, etc.). The fibre exhibits its normal properties of drape, softness and
strength.
2.14.6 Advantages and Disadvantages of Microencapsulation
Although there are many advantages in fibres and fabrics that contain microencapsulated PCM, there are a few disadvantages of the process, which are discussed
below.
2.14.6.1 Fibres
Advantages
• The PCM is permanently embedded within the fibre.
• The process parameters during spinning, knitting, dyeing, etc., are not altered for
the fibres containing the microcapsules of PCM.
• The fabrics produced from the yarn containing the microencapsulated PCM in
the fibres show the normal properties of drape, softness, comfort, etc.